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Related papers: Towards Dynamic PET Reconstruction under Flow Cond…

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In the context of dynamic emission tomography, the conventional processing pipeline consists of independent image reconstruction of single time frames, followed by the application of a suitable kinetic model to time activity curves (TACs)…

Applications · Statistics 2018-08-28 Michele Scipioni , Stefano Pedemonte , Maria Filomena Santarelli , Luigi Landini

Dynamic PET enables the quantitative estimation of physiology-related parameters and is widely utilized in research and increasingly adopted in clinical settings. Parametric imaging in dynamic PET requires kinetic modeling to estimate…

Image and Video Processing · Electrical Eng. & Systems 2025-12-23 Ziqian Huang , Boxiao Yu , Siqi Li , Savas Ozdemir , Sangjin Bae , Jae Sung Lee , Guobao Wang , Kuang Gong

In this paper, we introduce and study one-dimensional models for the behavior of pedestrians in a narrow street or corridor. We begin at the microscopic level by formulating a stochastic cellular automata model with explicit rules for…

Probability · Mathematics 2012-09-27 Alina Chertock , Alexander Kurganov , Anthony Polizzi , Ilya Timofeyev

We consider the inverse problem of estimating parameters of a driven diffusion (e.g., the underlying fluid flow, diffusion coefficient, or source terms) from point measurements of a passive scalar (e.g., the concentration of a pollutant).…

Numerical Analysis · Mathematics 2019-05-22 Jeff Borggaard , Nathan E. Glatt-Holtz , Justin A. Krometis

This study performs parameter inference in a partial differential equations system of pulmonary circulation. We use a fluid dynamics network model that takes selected parameter values and mimics the behaviour of the pulmonary haemodynamics…

Obtaining system parameters and reconstructing the full flow state from limited velocity observations using conventional fluid dynamics solvers can be prohibitively expensive. Here we employ machine learning algorithms to overcome the…

Fluid Dynamics · Physics 2024-10-17 Vladimir Parfenyev , Mark Blumenau , Ilia Nikitin

This work applies concepts of artificial neural networks to identify the parameters of a mathematical model based on phase fields for damage and fracture. Damage mechanics is the part of the continuum mechanics that models the effects of…

Materials Science · Physics 2021-07-21 Carlos J. G. Rojas , Marco L. Bitterncourt , José L. Boldrini

Direct reconstruction methods have been developed to estimate parametric images directly from the measured PET sinograms by combining the PET imaging model and tracer kinetics in an integrated framework. Due to limited counts received,…

Image and Video Processing · Electrical Eng. & Systems 2021-06-22 Kuang Gong , Ciprian Catana , Jinyi Qi , Quanzheng Li

PET suffers from a low signal-to-noise ratio. Meanwhile, the k-space data acquisition process in MRI is time-consuming by PET-MRI systems. We aim to accelerate MRI and improve PET image quality. This paper proposed a novel joint…

Computer Vision and Pattern Recognition · Computer Science 2024-08-23 Taofeng Xie , Zhuoxu Cui , Congcong Liu , Chen Luo , Huayu Wang , Yuanzhi Zhang , Xuemei Wang , Yihang Zhou , Qiyu Jin , Guoqing Chen , Dong Liang , Haifeng Wang

We present a framework for fine-tuning flow-matching generative models to enforce physical constraints and solve inverse problems in scientific systems. Starting from a model trained on low-fidelity or observational data, we apply a…

Machine Learning · Computer Science 2026-01-28 Jan Tauberschmidt , Sophie Fellenz , Sebastian J. Vollmer , Andrew B. Duncan

For several decades, image restoration remains an active research topic in low-level computer vision and hence new approaches are constantly emerging. However, many recently proposed algorithms achieve state-of-the-art performance only at…

Computer Vision and Pattern Recognition · Computer Science 2015-03-26 Yunjin Chen , Wei Yu , Thomas Pock

This paper is devoted to the investigation of inverse problems related to stationary drift-diffusion equations modeling semiconductor devices. In this context we analyze several identification problems corresponding to different types of…

Analysis of PDEs · Mathematics 2020-11-24 M. Burger , H. W. Engl , A. Leitão , P. A. Markowich

Most inverse problems from physical sciences are formulated as PDE-constrained optimization problems. This involves identifying unknown parameters in equations by optimizing the model to generate PDE solutions that closely match measured…

Optimization and Control · Mathematics 2024-03-12 Qin Li , Li Wang , Yunan Yang

Physics-informed neural networks have emerged as a powerful tool in the scientific machine learning community, with applications to both forward and inverse problems. While they have shown considerable empirical success, significant…

Optimization and Control · Mathematics 2025-12-11 Federica Caforio , Martin Holler , Matthias Höfler

The aim of this paper is to put the problem of vibroacoustic imaging into the mathematical framework of inverse problems (more precisely, coefficient identification in PDEs) and regularization. We present a model in frequency domain, prove…

Analysis of PDEs · Mathematics 2021-09-07 Barbara Kaltenbacher

The numerical simulation and optimization of technical systems described by partial differential equations is expensive, especially in multi-query scenarios in which the underlying equations have to be solved for different parameters. A…

Numerical Analysis · Mathematics 2025-04-09 Franziska Griese , Fabian Hoppe , Alexander Rüttgers , Philipp Knechtges

We present a novel parameter identification algorithm for the estimation of parameters in models of cell motility using imaging data of migrating cells. Two alternative formulations of the objective functional that measures the difference…

Estimating and quantifying uncertainty in unknown system parameters from limited data remains a challenging inverse problem in a variety of real-world applications. While many approaches focus on estimating constant parameters, a subset of…

Methodology · Statistics 2023-05-09 Andrea Arnold

A bacterial biofilm is an aggregate of micro-organisms growing fixed onto a solid surface, rather than floating freely in a liquid. Biofilms play a major role in various practical situations such as surgical infections and water treatment.…

Analysis of PDEs · Mathematics 2023-06-06 Tommi Brander , Daniel Lesnic , Kai Cao

We consider an inverse problem involving the reconstruction of the solution to a nonlinear partial differential equation (PDE) with unknown boundary conditions. Instead of direct boundary data, we are provided with a large dataset of…

Numerical Analysis · Mathematics 2025-07-30 Erik Burman , Mats G. Larson , Karl Larsson , Carl Lundholm